Maximal treadmill exercise with measurement of expired gases has been performed in more than 600 clinically normal BLSA volunteers over the past 5 years. Although a formal data analysis is currently in progress, it appears that the strong age-related decline in both maximal heart rate and maximal aerobic capacity (VO2max) noted in small BLSA examples will be confirmed. To determine the role of catecholamines in the well known age-related decline in exercise capacity, we measured plasma norepinephrine (NE) and epinephrine (E) at rest and during maximal treadmill exercise in 24 healthy men. Resting NE was not age-related but resting E was higher in men 68-77 years old than in those 22-37 or 44-55 years of age. At maximal effort both NE and E were higher in the elderly men. Furthermore, at submaximal workloads NE and E increased with age, both before and after normalization as a percent of peak VO2. In another study, the metabolic effect of relatively prolonged aerobic exercise, is being assessed in healthy men.